Rubbing machine



De@ 10, 1940? R. J. CHAMPAYNE .2,224,140

RUBBING MACHINE Filed May 15, 1939 2 sheets-sheet 1 Mmmm ha". f l, i

' @656m 50 0 n/ O m /oyQ/a//Wag/e I ToQgays DC# 10,f 1940 R. J. CHAMPAYNE 2,224,1 404 RUBBING MACHINE Filed May 15, 1939 Y 2 sheets-sheet 2 45 f have shown in the drawings and will herein de-V `Patented Dec. 10,1940

UNITED STATES PATENT oFFIcE f RUBBING MACHINE Roy J. Champayne, Rockford, Ill. Application May 15, 1939, Serial No. 273,701

11 claims. (Cl. 51170 in anovel manner from the pistons oi the fluid j motors by which it is reciprocated.. A further object is to provide a simpliiied and novel valve mechanism for controlling th'e applilcation of pressure :duid to the shoe actuators.

v The invention also residesin the novel arrangement of the cylindersiof thefluid actuators, the passages leading to and from the valve mechanism, and the manner of holding an abrasive sheettothe rubbing shoe.

Other objects and advantages of the invention will become apparent from the following' detailed description taken inconnection with the accompanying drawings, in which Figure 1 is a perspective View of a rubbing ma chine embodying the novel features of the present invention. I Fig. 2 is a longitudinal section taken along the line 2-,2 of Fig. 8,.

Figs. 3 and 4 are fragmentary sectional views Figs. 9 and 10; are sections'takeny respectivelyV along the lines 9--9 and I-I of Fig. 2.

Fig. 11 is a fragmentary plan section along the line II-.II `of Eig. 10.

taken While the invention is susceptible of various Vmodifications and alternative constructions, I

scribe in detail the preferred embodiment. It is tobe understood that I do not thereby intend to limit the invention by'such disclosure, ,but aim to cover all modiiications and alternative construcfor reciprocation'by a pneumatic actuator housed within a casing 4 by which the tool may be grasped conveniently and moved about or pressed against thework surface to be treated. For this purpose,

' the casing preferably has a rounded top- 5 and ribbed side surfaces E and is of a. width such as to tV naturally in the operatorshand with the thumb and fingers gripping opposite sidesof the casing. "Y 1 Herein, the abrasive carrier 3 is disposed immediately below the open bottomof the casing 4 and comprises a generally rectangular casting of light metal such as aluminum made rigid by upstanding side flanges I and 8 and front and rear end flanges 9 and I0 integrally connected at oppo-V site ends. lA pad 2 ofV yieldable material such as sponge rubber is attached by suitable adhesive to the flat bottom of the carrier 3. The abrasive The rear end bends around a transverse rib II against which the sheet is held by aj latch I2pivi oted on screw pins I3 'supported by the side iianges 1 and 8. Torsion springs I4 coiled about the pins press the latch downwardlyfto clamp thesheet around the rib I I and against thesurface of' a slot I5 in the latch. By raising and lowering a rearwardly projecting haridleIZa on the latch, the abrasive sheet mayV be released ,from or clamped effectuallyto the carrier. Y `1 To tighten the sheet, its other end is wound around a roller I6 journaled in bosses at the forfward ends of the side iianges and having an elongated diametrical slot I'Ithrough which the sheet may be threaded. The sheet is tightened by turn- I ing athumb knob I8 on one projecting end of the roller which may be locked in 'adjusted position by a disk I9 havinga periphery roughened by knurling or serrating and mounted on a screw 2| to` rotate on an eccentric" axis disposed adjacent and extending parallel to the roller. After the Y abrasive sheet is stretched on the pad 2, the disk is turnedto wedgeits periphery against serrations orknurling 20 on the knob, andthe screw 2| is then tightened to clamp the disk frictionally against the side iiange 8, This mode of attachlment iirmly holds the 'abrasivef'sheet in place while facilitating ready removal Vand replacement of the sheet and theuse` of a sheet of .minimum length. Likewise, any slack that develops by stretching of the sheet in service use may be taken up conveniently by releasing the locking disk and further turning the knob I 8.

Tne abrasive carrier is supported for reciprocation by a casting 22 which constitutes the body or block of the pneumatic actuators and is housed within the casing 4. being secured to the latter by screws 23 threading into the body or ears 24 thereon. The block is bored at opposed ends to form two pairs of cylinders 25 and 26 disposed in a common horizontal plane with the cylinders of each pair spaced laterally and the corresponding cylinders of different pairs alined longitudinally. Pistons 2l and 28 are Islidable inthe cylinders and project from the remote ends thereof into abutment with the flanges I0 and 9 to which they are fastened by cap screws 29 threading into the pistons which are preferably made hollow to reduce their weight. Washers 30 of leather or the like are clamped by nuts 3| against the inner ends of the pistons to form an eiective seal between the .pistons and the cylinder walls. Fluid for lubricating the sliding surfaces is admitted to the cylinders through vertical tubes 32 threading into holes in the block 22 communieating with the cylinders. The upper ends of the tubes project into holes in the top of the casing 4 and are equipped with ball check valves 33 through which 'fluid may` be introduced conveniently. j j

-It will be observed that the cylinders'25 and 26 provide guideways for the reciprocating shoe which ways are of substantial length and laterally spaced so as to provide a rugged four point mounting by which the abrasive shoe is guided accurately and held eiectually against tilting relative'to the block 22 and the casing 4. The pistons and cylinders also constitute four pneumatic motors for' reciprocating the shoe, two

operating in one direction and two in the other. Y

To produce one stroke, pressure fluid is admitted through passages 34 `to the closed ends of cylinders 25 while passages 35 communicating with the closed ends 'of the'cylinders 26 are open. During the other or reverse stroke,l uid ows into the cylinders 26 through the passages 35 and'at the same time, Vthe cylinders 25 are exhausted through the passages '34.

Such flow of the fiuidiscontrolled by a novel valveme'chanism actuated by the reciprocating shoe and arranged torserve all four pneumatic actuators. In the present instance, the valve mechanism includes a sleeve 36 fixed in a, bore 3l in the block 22 disposed between the adjacent closed ends Yof the two pairs of cylinders and preferably extends horizontally and transversely of the cylinder axes. The bore communicates with the four passages 34 and 35 with an exhaust passage I39 opening downwardly from the block 22 and with an upwardly. extending fluid "supply passage 39. Holes 40 and 4| in the sleeve register with the passages 38 and 39 while slots 42 and 43 register with the passages 34 and 35. The supply passage 39 is connected at its upper end with a bore 44 which communicates through a needle valve 45 (Fig. 11) with a passage leading to a fitting 46 projecting through the rear endV of the casing 4 and connected toa hose 4l extending tok thev compressed air supply. Thel needle valve member threads through a bushing 48 in the motor body 22 and may be adjusted to regulate the-air now to the motors by turning a knob 49 conveniently accessible from the exterior of the casing 4. Y f

Oscillatable withinthe sleeve 36 is a valve member 50 preferably having an enlarged head 5| at one end projecting from the sleeve and clamped by'a washer 52 against the sleeve end. The other end of the sleeve is closed by a washer 53 clamped against the sleeve by a screw 54 in this instance threading into a head 55 on the other end of the valve member 50. Intermedate its ends, the valve member is herein milled to a generally triangular cross-section to form equally spaced longitudinally extending lands 56, 51, and 58 bearing against the inner wall of theV sleeve. The sides 'I9 of the member lbetween the lands cooperate with the interior of the sleeve to form longitudinally extending passages 60, 6|, and 62. The passage 60 is separated from the others by the lands 51 and' 58 while the passages 5| and 62 are connected at all times through the hole 4| owing to the narrow width .of the land 59.

Vsupply passage 39 through the port 4|, the passage 6I, the slot 42, andthe passages 34 to the cylinders 25 causing the abrasive carrier to be shifted to the right as viewed in, Figs. 2 and 3. In this movement, air is forced out of the cylinders 26 through the passages 35, the slot 43, and the exhaust outlet 38.

In the reverse oscillation of the valve member toward the counter-clockwise limitl (Fig. 4), the slot 43 is connected to the supply port 4| to admit compressed air to the cylindersf26 and cause the carrier to be. shifted tol the left.I Air from Y the cylinders 25 is, during this movement,l ex- -hausted through the passages y34, the slot 42. and

the port 40.

In case means, other than the lands themselves, are provided for supporting the valvey member within the sleeve 36,. it will be apparent that the land 59 may be omitted. The valve passages 6,1 and 62 would thus be combined into l AAutomatic shifting lof the valve member between its limit positions (Figs. 3 and 4) is effected in the present instance by an arm 64 rigid with and projecting downwardly from thev head 5| beyond the end of the sleeve 36. 'I'he lower ball-shaped end 65 of the arm is received snugly in a socket 66 formed by a tube 6`|V which herein is on the free end of an arm 68 extending transversely of the direction of reciprocation of the `shoe between the castings 3 and 22 and pivoted on a screw 69 threading into the carrier 3. During normal operation, the socket 66 is fixed relative to the carrier by a. spring 10 stretched between the arm 68 and the flange 9 to'hold the arm against a stop lug 1| on the carrier.

. By virtue of this direct mechanical connection, the valve member is shifted clockwise Within the of the abrasive -shoe, the connection isdirect andV normally non-yieldable in either direction. That is to say, there is no lost motion between the motion transmitting parts. Nor does the valve movement snap over-center and dwell in a limit position while the direction of motion of the` carrier is being reversed as is commonly the casein prior pneumatic tools of the present character. On the contrary, the valve member follows all movements of the carrier in normal` operation. Thus, after the member has been shifted toits clockwise limit (Fig. 3) to `initiate movement of the carrier to the right, the valve member reverses immediately and thelands 51 and 5,8 lstart tocoverthe slots 4,2 and 43 respectively and `decrease the fluid flow to the cylinders 25.` This iiowis cut off completely by the time the carrier makes its mid-position (Fig. 2), andas the member is carried beyond this position bythe momentum'of the parts, air is` admittedgradually to.

`the cylinders 26 in which the pressure builds up to cushion the right hand stroke and initiate the left. stroke. Then, the reverse action occurs, pressure fluid ilowinginto the cylinders 26 through slot"r 43 and the passages 35 and the air in the cylinders 25 being exhausted` through the passages 34 'and the slot 42. As a result, the abrasive carrier reciprocates through a Very short range which is` suiiicient, nevertheless to produce effective abrading action. However, due to the direct connection to the valve member, there is nddwellf-` ing of the latter in either limit positionso that the period of reciprocation is reduced substantially as compared to prior devices of like character. ,In fact, reciprocation of the` carrier occurs sorapidly that the vibration is not objectionable.

Because of the direct valve actuating connection above referred to, the abrasave carrier will, asan incident to cutting off the airsupply, al-

= `ways stop with the valve member 50 centered- (Fig. 2) .n In this position of the valve, the pneumatic motors will not start againautomatically when the needle valve is opened -to admit compressed air, and it isy diflicultito shift the carrier` 4 0 sufficiently to move the valve.` To facilitate start-J 5() When the handle is released, the spring reestabv ing under this condition, the free end 13of the arxnis projected outwardly through a hole 14 inthe side ange 8 (Figs. l and `8) so as to be accessible for manual actuation of thearm against relative to the carrier 3 in a direction away from the lug 1l thereby moving the valve` member to the position shown in Fig. 4 to start the motors.

lishes the normal fixed relation between the shoe and valve. I claim as my invention: 1. A rubbing machine having, in combination, a

pair of cylinders arranged end to end, pistons reciprocable in said cylinders and projecting from the remote ends thereof, a rubbing shoe disposed below said cylinders and supported from the projecting ends of said pistons, a pressure fluid supply passage, a valve disposed between the adjacent ends of said cylinders and having a member oscillatable about a substantially horizontal axis 75 tween the adjacent` ends of said cylinders, fluid the action of the spring 10.` Bypulling back-A l wardly on the handle 13, the arm is thus shifted` inlet and exhaust joutletpassages communicat-` i moved inopposite directions away from 'such psitions and simultaneously connect the other passage to said outlet and inlet respectively.

3. A rubbing machine having, in combination, a pair of cylinders arranged end to end and closed at adjacent ends and open at their remote ends, pistons reciprocable in said cylinders and projecting from said remote ends, Aa rubbing shoe disposed below` said cylinders and supported from the projecting endsof said pistons, a bore disf posed between the adjacent ends of said cylinders and extending parallel to the plane of Areciprocation of said shoe, a fluid inlet and an exhaust out let communicating with said bore on the upper and lower.` sides thereof, ports in opposite sides of said bore each disposed between said inlet 'Y and outlet and respectively communicating with the closed ends of said cylinders, and a valve member rotatable in said bore and oscillated back and forth in timed relation to the reciprocationof said shoe, said member coacting with the wall of said bore to provide two passages, one in constant/ communication with said exhaust passage and connected to said ports alternately in the oscillation of said member, the other passage being in constant communication with said i inlet and connected to saidports alternately in the oscillation of said member.

4. A rubbing machine having, incombination, 7

four cylinders arranged in pairs with thelcylinders of the different pairs arranged end to end,

pistons reciprocablein said cylinders and projecting from the remote ends thereof, a rubbing shoe disposed below saidA cylinders and supported by said pistons, a bore disposed between the ad- '1 jacent ends of said cylinders and extending across the cylinder axes, a fluid ,inlet and an exhaust outlet communicating with said bore, ports opening `into said bore on opposite sides thereof ben' tween said niiet and exhaust passages and respectively communicating with the closed ends of one pair of cylinders, and rotary valve members rotatable in said bore and oscillated back and forth in synchronism with the reciprocation of said shoe to connect said inlet alternately to the ports of the different pairs of cylinders and simultaneously connect said other ports` to said outlet.

5. A rubbing machine having, in combination,

'four cylinders arranged in pairs with the cylinders of each pair spaced laterally and the corresponding cylinders of the pairs arranged end to end, pistons` reciprocable in said cylinders' pistons, whereby said cylinders constitute guideways slidably supporting said holder at points spaced both longitudinally and laterally of the i. direction of reciprocation, and valve means actu-` ated autornatlcally in response to reciprocation of said holder to admit pressure fluid first to the inner ends of the cylinders of one pair and then v valve means controlling the admission of pressure fluid selectively to the inner ends of at least two of the cylinders.

.7, Ay rubbing machine having, in combination,

a reciprocably mounted rubbing shoe, a reversible pressure fluid actuator connectedto said sh'oe and operable to move the shoe in opposite directions, a .valve having a member vmovable in opposite directions to reverse the'admission of pressure iiuid to said actuator, and a motion transmitting connectionbetween said member and said shoe including a spring and a part yieldable against the action of the spring to permit manual actuation of said member independently of the shoe out of neutral position, said spring normally maintainingsaid connection to cause said member t'o mov in unison with the shoe.

8. A rubbing machine having, in combination, a reciprocably mountedrubbing shoe, a reversible pressure uid actuator connected to said shoeand operable to move the shoe in opposite directions, a valve having a member movable in opposite directions from a neutral centered position to admit pressure fluid to the actuator, and a motion transmitting connection between said member and said shoe normally. operable to maintain a fixed relation between the memberand shoe so as to move the member back and forth in unison with the shoe but yieldable to permit manual actuation of said member independently of the shoe out-o neutral positionI whereby to initiate reciprocation of the shoe.

9. A rubbing machine having, in combination, a pair of cylinders arranged end to end, pistons reciprocable in said cylinders, a rubbing shoe supported by said pistons, a bore disposed between the adjacent ends of said cylinders and having a pressure fluid inlet and an exhaust outlet angularlyspaced apart and opening into said bore, ports in said bore respectively disposed between said inlet and outlet on different sides of the bore and communicating with the closed ends of the respective cylinders, a valve member rotatable in and having angularly spaced lands closing said ports when the member is disposed inv a cen` tral position, said member having recesses betweensaid lands` connecting said ports to said inlet and outlet respectively when said member is moved out of said position in one direction and connecting the same ports to said outlet and inlet respectively when the `member is disposed out of said position inthe opposite direction, and

means connecting said member and said shoe and normally operable without lost motion to oscillate the member and cause it to' fo1low all re-` ciprocatory movements of said shoe.

10. A rubbing machine having, in combination,

a reciprocably mounted rubbing shoe, pressure uid actuators connected to said shoe and respectively operable to move the shoe in opposite directions, a source of pressure fluid, a valve having a member movable in opposite directions `from` A a neutral central position to admit pressureiluid from said source to the respective actuators, and

va direct mechanical motion transmitting connection between said member and said shoe normally operable without Ilost `motion'to cause thel member to i'ollow all movements of the shoe. l

11. A rubbing machine having, in combination, an abrasive carrying shoe, a reversible pneumatic actuator for reciprocating said shoe having two cylinder chamber-aand a valve 'controlling theA admission of pressure uid first to one chamberl and then to the other comprising a cylinder hav-l angular position of the member and to reverse the connections in another position, said supply ports and said exhaust ports being disposed on one side of a diameter of said cylinder and, said inlet` port being disposed on the opposite side whereby the pressure of the iiuid entering said inlet urges said 'member against the opposite side of said cylinder to form an effective seal between sai supply ports.

ROY J. CHAMPAYNE. 

